Method of manufacturing wrought iron



Juiy 31, 1923. 1,463,228

A. $AUVEUR METHOD OF MANUFACTURING WROUGHT IRON Filed Jan. 31. 1922Patented July 31, i923.

UNITE ALBERT SAUVEUR, OECAMBRIDGE, MASSACHUSETTS.

METHOD or mancr'acronmc wnonenrmon.

Application filed January 31, 1922. Serial No.. 532,937.

T all whom it may concern: Be it known that I, Annen'r SAUYEUR, a

citizen of the United States of America, and. resident of Cambridge, inthe countyv of Middl-esex and State of Massachusetts/(have invented newand useful Improvements in Methods of Manufacturing Vi-ought Iron,

of which the following is a specification.

My invention relates to the manufacture of wrought "iron, and consistsof an improved process by which wrought iron may be made as an immediatecontinuation of and supplement to. the long-practised Bessemer processof conversion oi pig iron into steel. Otherwise characterized, myinvention superposes what is essentially the last stage of apuddlingproccss upon the confversion process, without interruption, and

namely, the converter.

be described also. sundry both stages of this continued process will becarried outin one apparatus, In describing the preferably tion of themetalat a welding heat, elimination of excess: slag and furtherelimination of the residual small percentage of carbon,

Inits physical and chemical constitution,

the product of the herein described processis the same, and responsiveto the same treatment, as the ball from a puddlmg furnace.

In the drawings hereto annexed, which illustrate'my invention,-

Figure 'l represents, in secliom a bottom blown Bessemer converter,characterized by sundry novelmodifications to be described, theconverter-is here shown in its upright position. y,

I Figure 2, represents the same, tilted on llH trunnions to'an inclinedposition, but not. enough todischarge its contents. t

Figure 3, represents the sa ine, tilted 1n the aspect-"opposite to thatof r igure 2.

Figure l, represents the same, completely inverted to discharge itscontents, and

Figure 5, represents the converter inside elevation. V The converter isan ellipsoidal'vessel C, in general proportions and contour not unlikethe Bessemer converters generallyused. In the manufacture of Wroughtiron ball, the size of the apparatus should be such that the balldelivered maybe of practicably.

wieldy proportions: Its discharge opening M should, by preference, berelatively larger than intheusual case, and be placed somewhat furtherto one side, from the longer axis of the vessel.

The wind-box B and tuyeres connected therewith, is located to OnesidB;and on the same side of the longer axis as the discharge OPeningIMQ vvThknown type of side-blown converter can be advantageously employed. Onthe other side of the converter vessel, projecting into its interior,about -midway between the tuyeres and the dischargeopening, there isprovided a weir R. The proportions and location of this weir are subjectto variations with n practicable limits, the essential point being, thatwhen the converter is tilted so that its longer axis approaches thehori-- zontal, the weir shall lie across the then lower side of theconverter, so as to constitute an obstacle to the flow of liquidmaterial from one end of the converter toward the other. I

Such an apparatus as is above briefly de- 'scribed will be found.adapted to the performance of my new process. Molten-pig iron is chargedinto the converter in the usual manner, the air blast turned on, and theconverter swung to its uprightposition as indicated in Fig. 1. Here thechargeof molten pig ironis designated at I. The reduction ofits carboncontent and other nonlerrous, elements proceeds in the mannercharacteristic of Bessemer action. If it be ctmsidered advisable, theair blast may be moderated sons to avoid O'l')j00l7l0l1 of slag andoxide formed during the oxidation, for

thereason that, retention of this material is,

essential to, or at least beneficial in, the final stages of thecontinuous process. The preliminaryobject is, to produce a low-carbonsteel byllessemer action, while retaining in the converter and mixedwith the iron, the

material which may rmmprehensively he termed slag, and which contributesto deearbonization of iron, under suitable atmospheric conditions, bytransferring oxygen fromv the air to the iron. with which it is mixed.Particularly with respect to the secondstage of my process, presently tobe described, a proportion of such slag suitable tothe development ofwrought iron ball. thoroughly distributed through the iron, is required.The amount of slag requisite may be produced in the converter as anincident to the Bessemer action; it may, however, be wasteful toprotract the Bessemer action, at the expense of iron, until therequisite proportion of slag is produced, and therefore, the process maybe enhanced economically by introducing slag, or other suitableoxidizing substance of any desired composition, into the converter atany stage consistent with the fusion of such introduced material,preferably after the Bessemer action.

A mild steel, mixed with slag, having thus been prepared in theconverter the converter is swung toward a horizontal position, so as touncover the tuyeres. The blast of air through the charge then ceases,and with this the further generation of heat ceases, and the chargebegins to cool. The converter, now functioning as a mechanical puddlingfurnace, is rocked back and forth on its trunnions T, from the positionshown in Fig. 2, to that shown in Fig. 3, and vice versa; causing'themixture of mild steel and slag to cascade back and forth over the weirR.

The importance of beginning this rocking motion and cascade actionimmediately after the air blast ceases to play through and keep stirredthe charge of mixed components, characterized by very discrepantspecific gravities, and of continuing the in termixture by sustainedcascade-action, will be obvious when the final. object of the process iskept in view, viz: the production of a pasty wrought-iron ball throughwhich slag is uniformly distributed. 'As the charge in. theconverter-vessel cools, it becomes pasty, and when it has been thusworked as long as is necessary or considered advisable, the convertervessel is inverted, as in Fig. 4;, over a traveling table P, or othercarrying device; which conveys the ball to the squeezer, hammer, pressor IOlls where it is finally worked into wrought iron in the usualmanner.

Since it is not permissible to allow molten metal to enter'the tuyeresof a converter, the wind-box and tuycres may with advantage be placed atone side of the longer axis of the apparatus. Thereby, also, a greateravailable cubic-capacity for Working the metal duringv thecascade-agitation stage of the process, will be provided. In thesideblown converter the wind-box and tuyeres are placed at one side, andbecause of this feature it is well adapted to the conduct of my process.Side-blown converters being moreover of smaller capacity than the usualbottom-blown converters may be preferred to bottom-blown convertersowing to the mechanical difliculties of working the very large ballwhich the latter would supply. Maintenance of the air blast (whateverthe position of the tuyeres), will guard against entrance of iron to thetu yeres, and the blast.

may be continued for this precautionary purpose, even though the tuyeresbe located at one side, and thus above the general level anduninterrupted, and by applying to the manufacture of wrought iron themost rapid method of refining and decarbonization known, namely, theBessemer process. I

hat I claim and desire to secure by Letters Patent is:

1. The method of manufacturing wroughtiron ball, characterized by thefollowing operations: reducing the carbon-content of molten pig iron toa low percentage by Bessemer action, retaining slag and iron oxideproduced by said action. in the decarbonized iron; lowering thetemperature of the mixture of decarbonizcd iron and slag, whilesubjecting it to continued cascade agitation and thereby maintainingmutual dis tribution of the said components.

2. The method ofimlnufacturing wroughtiron ball, characterized by thefollowing operations: reducing the carbon content: of molten pig iron toa low percentage by Bessemer action.

retaining slag and iron oxide produccdby said action, in thedecarbouizcd iron and adding oxidizing material to the mixture; loweringthe temperature of the mixture of decarbonized iron and slag. \whilesubjectin it to continued cascade agi tation and thereby maintainingmutual distribution of the said components:

Signed by me at Boston, Massachusetts, this twenty-third da" of January,1922.

' Al BERT SAUYEUR.

